Radiologically-Detectable Sacroiliac Involvement in Behcet's Disease

Background:TheassociationofBehcet’sdisease(BD)andankylosingspondylitis(AS)isstill a matterofdebate. Objective: As the presence of sacroiliac joint (SIJ) involvement is an essential criterion in diagnosis of AS, we decided to determine the prevalence of SIJ involvement in BD and compareitwiththatofa controlgroup. Patients& Methods:Werandomlyselectedtwogroupsof199BDpatientsand168non-BD cases (the controls). All caseswereover20years ofage.Standard anteroposterior radiographs of the SIJwereobtainedand interpretedbytwo rheumatologistsand a radiologist blinded to thediagnosis.Todetermine the severity of the condition, the following 5-point scale was employed: Normal (0), pseudo-widening (1), sclerosis (2), erosion (3), and bony fusion(4).Toeliminateanydoubts,onlygrades3 and4 wereconsideredassacroiliitis.Both groups were separately evaluated for age (30, and >30), and gender. Results were comparedusingChisquaretest. Results:Thegroupswerematchedforageandsex:Therewere98(49.2%)femalesinBDvs. 91 (54.2%) in the control group (p=0.35). The mean±SD age was 35±8.3 years in BD and 35±10 in control group (p=1).The SIJwas involved in 9 (4.6%) patients inBD and 7 (4.2%) patientsincontrolgroup(p=0.93).Comparisonsbetweentheresultsoftheunisexualcohorts revealed no significance either (p=0.68 for males, and p=0.64 for females). The age subdivisions (under-andover-30)againshowednosignificantdifference(p=0.96andp=0.69for under-andover-30patients,respectively). Conclusion:ThepresenceofradiographicsignsofSIJinvolvementisnotmandatoryforthe diagnosisofAS.